Skip to main content

Security Through Obscurity

I have been reminded recently, while looking at several products, that people still rely on the principle of 'security through obscurity.' This is the belief that your system/software/whatever is secure because potential hackers don't know it's there/how it works/etc. Although popular, this is a false belief. There are two aspects to this, the first is the SME who thinks that they're not a target for attack and nobody knows about their machines, so they're safe. This is forgivable if misguided and false. See my post about logging attack attempts on a home broadband connection with no advertised services or machines.

The second set of people is far less forgivable, and those are the security vendors. History has shown that open systems and standards have a far better chance of being secure in the long run. No one person can think of every possible attack on a system and therefore they can't secure a system alone. That is why we have RFCs to arrive at open standards that work. An example of a product that failed due to this is DiskLock. This was a few years ago now, but there are modern products that follow a similar philosophy. However, it's not my intention to pick on a particular vendor or product. DiskLock, though, was a program that encrypted files with the DES algorithm. No problems there, but they stored the key with the file, relying on people not knowing this or the scheme used to hide it. Unfortunately, with reverse engineering and chosen-key/plaintext attack techniques this is possible to work out. The problem is that the secrecy won't last long and when that has been bypassed the system should remain secure. If it does, then there was no need to keep it secret in the first place.

The only other time this phrase is used is when talking about the level of security given by implementing NAT. Here the addresses of the internal machines are obscured and an attacker doesn't know how many machines are there or what the internal topology is. Of course NAT will only allow outgoing connections or connections to specific ports due to port forwarding, so that does reduce the chances of attacking some machines. However, a web server will still have ports 80 and 443 open and, if it isn't properly patched, will suffer in exactly the same way as if it wasn't behind NAT.

I'm not saying that you should tell everyone exactly how you have implemented your security, but you can't rely on secrecy to last. The important thing is to thoroughly test your security, preferably with an outside independent agency. This is particularly important if you want others to rely on your system and must include an audit of your code for software and settings for your hardware. Are customers more likely to trust an independent testing agency or a vendor trying to sell a product or system?

Comments

Popular Posts

Trusteer or no trust 'ere...

...that is the question. Well, I've had more of a look into Trusteer's Rapport, and it seems that my fears were justified. There are many security professionals out there who are claiming that this is 'snake oil' - marketing hype for something that isn't possible. Trusteer's Rapport gives security 'guaranteed' even if your machine is infected with malware according to their marketing department. Now any security professional worth his salt will tell you that this is rubbish and you should run a mile from claims like this. Anyway, I will try to address a few questions I raised in my last post about this. Firstly, I was correct in my assumption that Rapport requires a list of the servers that you wish to communicate with; it contacts a secure DNS server, which has a list already in it. This is how it switches from a phishing site to the legitimate site silently in the background. I have yet to fully investigate the security of this DNS, however, as most

Web Hosting Security Policy & Guidelines

I have seen so many websites hosted and developed insecurely that I have often thought I should write a guide of sorts for those wanting to commission a new website. Now I have have actually been asked to develop a web hosting security policy and a set of guidelines to give to project managers for dissemination to developers and hosting providers. So, I thought I would share some of my advice here. Before I do, though, I have to answer why we need this policy in the first place? There are many types of attack on websites, but these can be broadly categorised as follows: Denial of Service (DoS), Defacement and Data Breaches/Information Stealing. Data breaches and defacements hurt businesses' reputations and customer confidence as well as having direct financial impacts. But surely any hosting provider or solution developer will have these standards in place, yes? Well, in my experience the answer is no. It is true that they are mostly common sense and most providers will conform

Trusteer's Response to Issues with Rapport

I have been getting a lot of hits on this blog relating to Trusteer's Rapport, so I thought I would take a better look at the product. During my investigations, I was able to log keystrokes on a Windows 7 machine whilst accessing NatWest. However, the cause is as yet unknown as Rapport should be secure against this keylogger, so I'm not going to share the details here yet (there will be a video once Trusteer are happy there is no further threat). I have had quite a dialogue with Trusteer over this potential problem and can report that their guys are pretty switched on, they picked up on this very quickly and are taking it extremely seriously. They are also realistic about all security products and have many layers of security in place within their own product. No security product is 100% secure - it can't be. The best measure of a product, in my opinion, is the company's response to potential problems. I have to admit that Trusteer have been exemplary here. Why do I